Your AP is running ZoneDirector firmware so cannot be configured directly with WLAN (and other) details as this configuration is pushed from the controller.
As mentioned by Elvert; you will need to install (upgrade) a new firmware version on to the AP so it can operate in 'stand-alone' mode. This is either the stand-alone firmware e.g. Stand-alone 220.127.116.11 or Unleashed 200.9. Both are available on the Ruckus support site, if you have a support contract allowing you access.
Actually, the main thing is that you need to factory reset AP, when it is in status "managed by ZD", web interface is disabled. After factory reset by button it becomes available. You can configure basic things than, but it is much better to install Unleashed firmware, than you'll have much more features and even phone app for management.